class_docstr: Represents an interest rate curve.
code: def curve_type(self) -> curve_types.CurveType:
      return self._curve_type
  
imports: from typing import Optional, Tuple
  import tensorflow.compat.v2
  from tf_quant_finance import datetime
  from tf_quant_finance import math
  from tf_quant_finance import rates
  from tf_quant_finance.experimental.pricing_platform.framework.core import curve_types
  from tf_quant_finance.experimental.pricing_platform.framework.core import daycount_conventions
  from tf_quant_finance.experimental.pricing_platform.framework.core import interpolation_method
  from tf_quant_finance.experimental.pricing_platform.framework.core import processed_market_data
  from tf_quant_finance.experimental.pricing_platform.framework.core import types
  from tf_quant_finance.experimental.pricing_platform.framework.market_data import utils
label_desc: Use image node_id 14 for calling the RateCurve obj's underlying member method code with example usage: obj.curve_type() and returns: self